OUR knowledge of the physiology of the human body has been so much enriched by pathological facts that we may truly say that some branches of it would, as far as we can see, have remained forever closed books if the effects of disease had not been observed. So it is with psychology in its turn. Since mental disease has been systematically studied, the science of the mind has undergone a veritable revolution. Having laid down its conceptions and having learned that psychical processes, like all other phenomena of Nature, are subject to definite law, psychology has made an effort to determine the law of the mental processes of genius and to frame a definition of genius that should take into account facts which are now scientifically established. Many attempts have been made to determine what genius is, from which various conclusions have resulted, but those inquirers who have sought to penetrate to its psychological laws and to explain its phenomena upon recognized psychological principles have been obliged at last to acknowledge that they had to do with the most diverse psychological conditions which have been promiscuously labeled as genius. The question whether the popular word genius can be used as a scientific term can be decided only by a psychological analysis of those poets, painters, virtuosos, scholars, statesmen, and generals who have been generally recognized as geniuses. Famous poets, observant of their own inward conditions, have often said that their works were composed as in a dream, unknown to themselves; that instead of being deliberately constructed, their ideas have, as it were, flown to them.

Involuntary thought is frequently described by the poets as unconscious. That can not be accurate, for "unconscious thought" is a contradictory phrase. Not even a dream can be said to be unconscious, whether it be purely ideal like most dreams, or produce action as in sleepwalking. In such a state self-consciousness alone is suspended, not consciousness itself. Fancy stands halfway between dreaming and active intellectual function. The latter depends directly on the will, while in the former the will is in total abeyance. All men are subject to fall under the influence of fancy. In ordinary men it makes day-dreams, which everybody recognizes to be opposed to purposive thought. All that fancy produces depends on former impressions of sense. It is powerless to create anything new; its products are mere combinations in memory of the residua of former impressions. They may be unlikely enough, and in that sense it may be true that its products are "original"; but this does not conflict with the facts alleged. It is this creative and somewhat independent power of fancy which lends to the work of art its character of originality, and hence it is that many inquirers have found in that the essence of genius.

The psychological analysis of famous poets will show that the intellectual function is no whit less important a factor of poetic genius than fancy itself, although the latter is the one immediately employed in the act of composition. We have seen that creative fancy works with the material which former impressions of sense have left behind as their remains or residua. The more comprehensive the knowledge of the poet, therefore, and the more he is in condition to assimilate and compact the impressions the world conveys to him, and the sounder and truer his judgments of persons and situations, and the more methodical his thought and the better his memory, by so much the more will his fancy display luxuriance, and so much more various will be his creations. Another psychical phenomenon, besides fancy and intellectual function, surprises us in famous poets—to wit, a refinement of the feelings, heart, and moods. We often find these qualities developed in great poets to a point we can scarcely imagine. Another trait remarkable in famous poets is an instinctive and invincible impulse to express the ideas and feelings within them. In consequence of this impulse, the work of genius is not a voluntary labor, but the "involuntary product of a psychical need. It is not a hankering after applause and success, nor a regard for his other interests, which induces the man of genius to perform his task. It is solely a passion to give shape and form to the idea that exists in his fancy. The true poet does not versify because he would, but because he must. The comparison of traits applied to a considerable number of typical "men of genius" leads to the conclusion that the word does not express any one psychological concept, and that nobody has succeeded in giving a pregnant definition of the quality or is likely to do so. As insanity is equally indefinable, and it is impossible to draw a sharp line between mental sanity and mental derangement, it may seem useless to attempt to compare two such indefinite quantities; still, the comparison may possibly enrich our knowledge and lead us toward a recognition of the truth.

It is no newfangled notion that genius and insanity are connected. It has been reiterated from Plato down. The chief condition of mental sanity is a well-proportioned development of the different psychical factors. But as in the development of the different mental faculties, so also in their proportion to one another, a certain latitude of health is to be allowed. In one man fancy is preponderant; in another, consecutive thought; while a third may have particularly strong feelings as his characteristic. Yet we have no reason to say that these minds transgress the border of health. It is the difference in the relation of the different psychical elements that makes the diversity of men's characters. Now, we know that there are no two characters in the world that are precisely alike. It follows that there is no norm for these relations. The higher the grade of development of the genius and of the individual, the more prominent will differences of psychical factors become, and a correspondingly greater latitude of health must be allowed.

A comparison is instituted between the different symptoms of exaggerated proportions in development which have been discovered in great men, and an endeavor to ascertain the distinctions between these and symptoms of insanity. Among these symptoms are hallucinations, to which the soundest of men have been found more or less subject, over-exuberance of fancy, and self-abandonment in the restless strife for some ideal goal. In great artists and scholars, on the one hand, and in the insane on the other, there is a great, irresistible impulse which fills them to overflowing and makes them forget all personal considerations. But while in the former the restless compulsion to create, the hot aspiration is the kernel of the highest and noblest perfection of man, in the latter there is a morbid impulse which is usually directed to the silliest things. Formerly such a state was called a monomania, since this irresistible impulse seemed to be the only pathological symptom; but careful observation has shown that there is always a more general psychical malady, usually the consequence of arrested development. It is perfectly astonishing with what tenacity and untiring persistence such, patients go to work. Those patients exhibit the same phenomena who may be termed inventors and Utopians. They not seldom sacrifice their means and bring themselves and their families to ruin by their unconquerable desire of making inventions and discoveries. They are fully convinced, in their folly, of the epoch-making importance of their improvements, and all pains are lost to cause them to desist from their ridiculous performances. In contrast with students, in whom the turning point of their mental action lies in the understanding, in artists moods and feelings are often the starting point of their productions. Hence we find that in them this part of the mental organ has not infrequently an enormous development. As with the other psychical characters, so likewise here we find that the high refinement of a single factor—always, however, in just proportion to the total action of the organ—produces outward phenomena having some similarity with those states which are due to disturbed inward equilibrium, and which we often have occasion to observe in the insane.

No doubt, poets and artists, as well as scholars, often exhibit an outward appearance of self-absorption and of indifference to their surroundings. This is common to them with many of the insane. But how disparate are the causes underlying these phenomena! With the weak-minded it is the want of power to concentrate the attention which renders them uninterested and indifferent to the outward world; but with poets and scholars it is, on the contrary, the high degree of that power which brings about similar phenomena. As we know, the centrifugal condition which we term attention not only extends its power to the organ of sense whose action is emphasized, but it must also be able to order off all the rest of the impressions of sense. The great thinker appears uninterested in surrounding things because his whole attention is directed to the well-ordered sequence of his logical thoughts, to which end, with fullest consciousness, the outward impressions are ordered off. The weak-minded man is present at a performance. The sounds of the words of the orator ring in his ears, but the slightest outward or inward impression suffices to make his attention wander. His thoughts ramble. They are everywhere and nowhere. The mentally gifted man, on the contrary, constantly has his mind on the matter in hand. If he wishes to concentrate his thoughts upon an outward object, nothing that takes place is able to escape him. Neither the psychologist nor the psychiatrist ought to be content to observe behavior superficially, but must trace out the motive of it in order to draw any inference from it. The most absurd conduct sometimes has reasons consistent with health, while conduct which would not surprise a layman at all may be regarded by a psychiatrist as a well-recognized symptom of insanity.

A further explanation of many peculiarities of men of genius is to be sought in their relations to the society in which they live. A man with a reputation for high talents, distinguished from his youth for his superiority and genius, always has his circle of admirers with its proportion of flatterers. If he had the misfortune to be a precocious child, he will have been accustomed from his earliest youth to the idea that his genius is far above ordinary men and above the rules that apply to those men. If such a man is, in later years, attacked by a competent critic upon this or that point, or if schools and parties are formed unfavorable to his method, whether in art or in science, he will, of course, react otherwise than a man would do who was accustomed to opposition of every description. He will, perhaps, regard his just critic as a personal enemy; he will complain that he is misunderstood by his contemporaries, and his passion may go so far that the public at large and superficial observers among psychiatrists may consider him to be the victim of a delusion of persecution.

Peculiar inclinations and other mental idiosyncrasies of men of genius can mostly be very readily explained. Everybody accustomed psychologically to study and dissect those whom he meets, so far as opportunity is afforded, is familiar with the remark that each individual of the human race has his peculiarities, more or less odd, his "weaknesses." The ordinary man, if he has the least breeding, has been accustomed from his youth up to hold in check one inclination or another which violates the usages of society, or even perhaps of good morals. He has learned to attend sufficiently to his own conduct not to allow habits to take root which might appear unusual or be disagreeable to others. But the man of genius is far too much governed by his inward processes, his fancy, and his work to pay attention to trifling details of manner. He therefore appears what he really is, while the average man would not do this. Consequently, chance peculiarities and special inclinations appear in the former more than in the latter.

Thus it is that the behavior of great men is not to be measured by the same standard as that of others, that we have to take account of the motives of their actions, and that the psychical conditions must be kept in view if we are to draw any trustworthy inferences from their behavior. Those mighty natures must be judged from their own organization, and not from, the Philistine point of view of the so-called average man.

As a further proof of the affinity of genius to insanity, it has been alleged that a great number of eminent men have actually had attacks of insanity. But the question is not whether there have been great men who were insane, but whether the proportion of those who have at some period of their lives been attacked by insanity of different types has been markedly greater or less among famous personages than among the general run of mankind. In order to decide this, we should be in a condition to state with exactitude what the percentage of insane among the total population was at a given period of history, how many men of genius there were at that time, and how many of these were insane. Such researches must be repeated at different times of history; then, if they were irreproachably exact and sufficient, it would be possible that some sound conclusion might be reached.

There has also been an attempt to trace a connection between genius and insanity through facts of heredity. In spite of some valuable works in this department, it must be admitted that the observations hitherto adduced are still far from sufficient to have any scientific value. The fact that in several families of eminent men insanity has occurred in no wise justifies us in drawing any conclusion. In order to do that, we must, as in the former case, be in a condition to establish statistical comparisons which shall be absolutely exact between the proportionate occurrence of insanity in the families of men of genius and those of ordinary men. Every disinterested observer must be struck with contradictions and the inadequacy of the investigations that have been made in this field.

It is true that between famous men—the so-called geniuses—and the insane many resemblances may be traced. Nevertheless, they are, as we have seen, mere resemblances, not real affinities. Just as every symptom of mental disease has its analogue in health, so has it also an analogue in genius. But, owing to the entire mental action being higher than in average men, the states analogous to morbid symptoms here come out more markedly. Genius resembles insanity as gold resembles brass. The similarity is merely in the appearance. When we go deeper into the facts we find the two states so widely disparate that we are not justified in saying that they are allied; still less, with Moreau, that genius is a morbid condition.

Finally, let the fact be considered that most of the great men, both of art and of science, were misunderstood by their contemporaries, and were only appreciated after they were dead. In recognition of this truth, Goethe pronounces that a genius is in touch with his century only by virtue of his defects, only in so far as he shares the weaknesses of his times. The genius of the truly great man outstrips, with its great wing strokes, the rest of the flock. Those who can not keep up with him can not comprehend him. They are puzzled at first, and finally set him down as a fool. In short, they confound genius and insanity.